For people who have certain medical conditions, there may be serious risks associated with driving a vehicle. For example, an epileptic may have a seizure while driving; and a diabetic may have a sudden drop in the blood glucose level, and thus lose consciousness, while driving. In general, older drivers, compared to younger drivers, tend to have a relatively higher chance of having a traffic incident due to medical emergencies. In case of such Sudden Medical Emergency (SME) incidents, the driver may lose control of the vehicle, thereby causing an uncontrollable traffic accident that may involve injuries or even casualties. Even for healthy drivers who are less likely to be subject to SME incidents, tiredness, drowsiness or fatigue due to prolonged driving and/or lack of rest may still result in temporary loss of focus and/or control of the vehicle. A split second of losing focus while driving, let alone losing control of the vehicle, may be enough to cause irreversible tragedy and forever remorse.
Even if an injury or casualty does not immediately occur in an SME incident where a driver of a vehicle loses control of the vehicle, in most occasions it remains dangerous to leave the vehicle in the traffic, or even in a driving lane, as an injury or casualty may possibly follow. For example, the driver may pass out due to an SME incident, and the uncontrolled vehicle may keep moving and eventually hit another vehicle or some roadside structure.